C# C Length Calculator错误/需要转换为double类型的对象

这是c控制台应用程序。我是编程新手。你们能帮我查一下这个吗？我错过了什么

这是程序说明：

•长度计算器

•允许用户将厘米转换为英尺和英寸

•英尺和英寸到厘米

•用户将选择其中一种转换或选择取消此选项

•如果用户选择转换，他们将输入适当的值。 因此，对于英尺和英寸到厘米，用户将首先输入英尺数，然后输入英寸数。 • 如果是6英尺，英寸数可能是0 •显示结果后，询问用户是否希望进行另一次长度转换，他们可以回答“Y”或“N”或等效的小写字母 如果是，程序按上述步骤进行。如果否，则返回主菜单

        public static double LengthCalculator() {

        double Centimetres = 0.0, Feet = 0.0, Inches = 0.0;
        string AnotherConversion; 
        string LengthCalculatorMenu;
        int LengthCalculatorOption = 0;

        do {
            LengthCalculatorMenu=("\n1) Convert centimetres to feet and inches "
                                + "\n2) Convert feet and inches to centimetres ");
            Console.Write(LengthCalculatorMenu);
            LengthCalculatorOption = int.Parse(Console.ReadLine());
            Centimetres = double.Parse(Console.ReadLine());
            if (LengthCalculatorOption == 1) {
                Feet = (Centimetres / 2.54) / 12;
                Inches = (Centimetres / 2.54) % (Feet * 12);
                Console.WriteLine("Please Enter the Centimetres that you wish to convert to feet and inches");
                Centimetres = double.Parse(Console.ReadLine());
                Console.WriteLine("\nThe equivalent in feet and inches is {0:C} ft {1:C} ins", Feet, Inches);
                Console.Write("\nWould you like to make an another conversion? \n\n(Enter Y to make an another conversion/Enter any other key to exit):");
                AnotherConversion = Console.ReadLine();
            } else if (LengthCalculatorOption == 2) {
                Centimetres = ((Feet * 12) + Inches)*2.54;
                Console.WriteLine("Please Enter the Feet");
                Feet = double.Parse(Console.ReadLine());
                Console.WriteLine("Please Enter the Inches");
                Inches = double.Parse(Console.ReadLine());
                Console.WriteLine("\nThe equivalent in centimetres is {0:C}", Centimetres);
                Console.Write("\nWould you like to make an another conversion? \n\n(Enter Y to make an another conversion/Enter any other key to exit):");
                AnotherConversion = Console.ReadLine();
            } else {
                Console.WriteLine("\n\a\t Invalid Option!Option Must be 1 or 2");
            }
        } while (AnotherConversion == "y" || AnotherConversion == "Y");
          return;
    } // end Length Calculator

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这里的问题是LengthCalculator方法被声明为返回一个双精度值，但实际代码实际上并没有返回任何东西

return;

要解决此问题，您需要使该方法无效或返回一个双精度值。我的直觉是你想要一个空返回方法

public static void LengthCalculator()